package collection;

import java.util.ArrayList;
import java.util.Collection;

/**
 * Collection接口的演示
 * Collection：是所有集合的顶级接口
 */
public class CollectionDemo {
    public static void main(String[] args) {
        Collection c = new ArrayList();
        c.add(new Point(1,2));
        c.add(new Point(3,4));
        c.add(new Point(5,6));
        c.add(new Point(7,8));
        c.add(new Point(9,0));
        c.add(new Point(1,2));
        System.out.println(c);

        Point p = new Point(1,2);
        boolean contains = c.contains(p);
        System.out.println(contains);//ture
        /*
        boolean remove(Object o:)----一般都不接收boolean结果
        从当前集合中删除与给定元素o的equals()比较为true的元素
        若存在重复元素则只删除一次
         */
        c.remove(p);
        System.out.println(c);

        Collection cc = new ArrayList();
        Point pp = new Point(1,2);
        cc.add(pp);
        System.out.println("pp:"+pp);
        System.out.println("cc:"+cc);
















        /*
        Collection c = new ArrayList();
        c.add("one");
        c.add("two");
        c.add("three");
        c.add("four");
        c.add("five");
        //集合重写了Object的toString()方法，返回格式如下：
        //[元素1.toString(),元素2.toString(),元素3.toString(),....]
        System.out.println(c);//[one,two,three,four,five]

        System.out.println("size:"+c.size());//5,?输出集合的元素个数
        //仅当size()为0时表示为空集
        System.out.println("是否为空集："+c.isEmpty());
        c.clear();
        System.out.println("集合已清空");
        System.out.println("size"+c.size());
        System.out.println("是否为空集"+c.isEmpty());
         */
    }
}
